I have a COBOL copybook which changes almost every month. Many COBOL programs are using this copybook, as a result of which I have to recompile all the programs every month. Is there a way to eliminate the need for recompilation every month.

Realistically, a copybook is normally used for code that is reasonably static -- using it for source that changes "almost every month" is going to require recompiling the programs that use the copybook. You might be able to set up a mass compile, depending upon your source management system, so you need to contact your site support group for assistance.

On the fly, i'm thinkink of a little Rexx-Proc. This one reads a Tso-Member wich includes the Program-Names you have to compile. One line for one name. Then for ervery line extracts the Program-Name and does File-Tayloring to build a Compile-Jcl and submits this Jcl via Internal-Reader.

Programs which are not using new-field don't need to be recompiled.
programs which are using new-field have to be modified anyway.
Only when you run out of filler, you need to change and recompile all.

Of course moving of all fields is now different from moving the record.

If you have enought FILLER to withstand many field additions for a while, and if the copybook changes involve adding new fields into the FILLER area, then programs which do not use the new fields need not be recompiled for technical reasons.

You certainly will need to manage which programs use which fields, but until the record length changes, non-affected programs are fine.

Given the vast number of programs and high frequency of field additions, I suggest you follow a policy other than "recompile everything no matter how trivial the copybook change." Any professionally run organization should be able to formulate and follow "standards" that meed their needs, as opposed to what everyone else does by rote.

some of the more expensive repository tools (endevor)
make it difficult to promote a copybook without also recompiling the programs that use it.

the cheaper tools (changeman) make it difficult to easily recompile everything, and still make it difficult to promote a new copybook without the recompilation.

now, we all know that using a filler and not changing the length technically is not a reason to recompile the world.
and before these nifty repository tools, that's what we did.

i agree that this should be left up to the organization,
as they know their least common denominator - programmers skill sets.

but on a forum like this, that is populated with people with little or no background in mainframe skills,
refuse to read documentation and try to understand concepts,
i think it is better to tell them the safe way - recompile the world.
why, because they will see one time where someone said something about
unnecessary compiles and from then on, that is what they do and end up in a world of hurt,
and lay the fault at one of our posts.

some of the more expensive repository tools (endevor)
make it difficult to promote a copybook without also recompiling the programs that use it.

Actually, Endevor doesn't even warn you if you promote an updated COPYBOOK without promoting all of the COBOL code that references it, but it will do its darndest to prevent you from promoting COBOL code with a retrograde COPYBOOK (that is, one that is either not being promoted simultaneously, or does not already exist at a higher stage) - and that, regardless of whether or not the code references any newly defined elements that used to be filler.
When promoting an element in Endevor, subordinate elements, like copybooks, MUST exist at a higher stage than the element being promoted. That's why the Endevor SCL is "sorted" (according to the Type Processing Sequence established by the Endevor Administrator) before being invoked. The "usual" sequence is that copybooks get promoted before cobol code, macros get promoted before assembler code, procs get promoted before runjcl, etc.